Anyone heating their property with a Heat Pump?

[Devon]

I am building a new place in the Charente maritime region and considering underfloor heating worked by a heat pump. Does anyone have any experience of this heating method, good or bad? Would I be better off with a conventional heating system and loads of insulation?

Thank's in advance.

 

[Framboise]

Do you mean geothermal heating?    If so our French neighbour has it.   Whilst it was very expensive to install once up and running he says its nice and cheap, the only drawback being if you switch it off for any reason it can take a day to get going properly again.   And yes its probably best to install this before you move in - he said it was terrible as they were in situ when it was done.

[lorna]

Forgive my non-technical reply. There has been good discussion of the various heating methods which you would find by doing a search.

Under floor heating can be driven by various methods including geo-thermal, boiler or heat-pump. You need a big garden or a field for geo-thermal. Pipes are laid underground to take the heat from the ground. Our heat pump is outside and looks like an air-conditioning unit. There is another part indoors about the size of a hot-water cylinder.

Last year was our first winter here and we discovered we had a partially working ch system. We have under-floor heating downstairs and radiators upstairs (the radiators didn't work). The system was driven by an oldish gas boiler. It was very expensive despite not working very well.

During the summer we had a heat pump installed and a new gas boiler and lots of insulation round the visible pipes which passed through a very cold garage. The heat pump part cost 17,000 euros including installation. The heat pump's effectiveness decreases as the outside temperature reduces and at minus a lot may not provide the amount of heat required. MOH checked temperature statistics going back quite a way and decided we would keep a boiler which can supplement the heat pump if it gets very cold.

I have read opinions that under-floor heating is the best method. It needs to be done when the house is built so you can do it with a new build.

We expect our heat-pump to be a lot cheaper but it will take a good few years to recoup the cost.

[Le Plombier]

Whilst expensive Geothermie is by far the best of the systems available on the market for energy conservation

This is the only alternative system I propose to my clients when central heating is required

Aerothermie efficiency varies and invariably requires a back up of a conventional boiler or an electric heater to make good the energy shortfall so the running costs remain relatively high. You can also experience noise problems due to the condenser fan

If you do not want the expense of Geothermie then you are best to have a conventional system and a well insulated house

Wood burners work well and are cheap to run but you have to consider loading the pellets in to the hopper frequently and what you are going to do to dispose of all the ash

Solar is good but only for hot water and swimming pools

Le Plombier

[Théière]

How about air source heat pumps? although you will have to dig up your floor for the under floor heat pipes at least you won't have to dig up the garden as well.

[powerdesal]

Air temperatures drop lower than sub surface ground temperatures hence the units will not be as effective at the worst time.

[Devon]

Thanks for the replys so far. My place is being built on rock so geotherm is not an option and the cost and lack of efficiency (in cold weather) seems to rule out an air exchange heat pump.

[Nick Trollope]

[quote user="teapot"]How about air source heat pumps? although you will have to dig up your floor for the under floor heat pipes at least you won't have to dig up the garden as well.[/quote]

Read Le Plombiers reply. In my experience, they do not work (in as much that there is not enough energy available in the air to heat a house without backup). They cost a fortune to run as a result (as the backup is usually electric). Geothermal (as in ground-source) is good, once you have installed it - but very very expensive to install from scratch - and if you can't use underfloor, it's efficacy is severly reduced.

My current "best bet" is wood pellets, which are not as inconvenient as LP suggests....

 

[Quillan]

In defence of Air pumps the newer inverter type units which have a better gas are 'A' rated and work down to -15 deg C and give a rate of just over 4.1, thats for every 1kw of electricity used you get 4.1kw of heat or cold out for the full external temperature range. You need to make sure you have the latest type of gas which is quite expensive and whos name escapes me. Like all these things the more you pay the better the kit. I have installed a couple and will let you know next week how well they run as we will be down to -2 or less with snow. Hopefully I will be a warm as toast.

I did look at the pellet boilers and you get a auto feed system for the hopper from a dry store outside so the lorry just tips into the store and thats it. Mind you it puts another couple of grand on to the price of the system.

[ams]

We have geothermal heating. An excellent system. Operating costs are about €30 per month for 24 heat. The system can be reversed in summer to cool the house. When we turn it off it normally takes about 4 hours to come back to full operation. In addition it also heats the swimming pool at a cost of about €5 per day.  We have had no problems so far, 5 years and no maintenance costs.

 

ams

 

 

[Théière]

Thanks Quillan, I was not thinking of the old type when I posted, I have seen the figures for the latest models and they do look impressive. I will certainly be interested in your reporting actual performance not (sales) performance.

[ams]

We live in the CM 17 and the local rock is calcaire, no problem in installation.

 

ams

[Albert the InfoGipsy]

Three comments:

Insulation is not an alternative to a heating system. Always insulate to the max whatever heat source you choose.

Insulation is not the only important thing - air-tightness (draught proofing) is at least as important.

A properly designed 'solar house' will reduce the requirements for fossil or electric heating.

Try posting your questions here:

http://www.greenbuildingforum.co.uk/newforum/

It's full of people who know what they are talking about when it comes to houses.

 

 

 

 

[powerdesal]

[quote user="Quillan"]

I did look at the pellet boilers and you get a auto feed system for the hopper from a dry store outside so the lorry just tips into the store and thats it. Mind you it puts another couple of grand on to the price of the system.

[/quote]

Quillan,

Whats the pellet availability like in France, last time I checked (a couple of years ago) it was very patchy, has it now improved?

[UlsterRugby1999]

Quillan - do you have any details of the actual air pumps and prices etc. Any information would be gratefully appreciated.

[krusty]

UL1999 ..... Some prices here

http://www.bricodepot.fr/bordeaux/electricite/climatisation-ventilation/climatiseurs-fixes

ps see also this thread in which Q has provided some good infomation

http://www.completefrance.com/cs/forums/1437089/ShowPost.aspx

[krusty]

PD here is a firm that will deliver pellets

http://www.biowood.fr/commander.php

[krusty]

[quote user="Quillan"]

You need to make sure you have the latest tyer of gas which is quite expensive and whos name escapes me. Like all these things the more you pay the better the kit.

[/quote]

The better gas is R410A

[UlsterRugby1999]

Cheers  krusty - I've only just started to research this whole area and there is just so much info about it takes an age to digest. I had actually seen these units in Chateauroux recently but assumed (wrongly) that they were simply air con units.

Is there a limit for the distance from the outside unit to the inside unit. For example, (assuming I wanted to install a BiSplit unit as described by Quillan in the other thread) to heat 2 rooms, 1 in front of the other - front to back, will the room furthest away from the outside unit suffer a lot in terms of less heat going to the room. If not, then is there any sense in searching for a bigger unit that would cater for say four rooms.

I also note that these units dehimidify. I take it that a drain kit is required too.

Wow - loads of questions - sorry [:$]

[Théière]

I was told by a pro installer that they test the systems once installed and often add a bit more gas to pep up the performance for rooms slightly further away, this is why extension pipes can be purchased. Only what I was told.

[UlsterRugby1999]

Cheers teapot -  thats sounds like I'd need specialist help after I'd installed the system myself. I'd rather expected an answer along those lines. Still - it still sounds do-able.

[Quillan]

Only the cheap ordinary unit comes with connection pipes the rest you have to buy pipes for. The standard pipe is 4M long which you can also get as a pre-filled pipe which although my catalog says is 120 Euros on the website its 160 Euros. you can also get unfilled pipes up to 6M which my catalog says are 79 Euros each. The connectors for them are 1/4 - 3/8 or 1/4 - 1/2 and I believe are BSP threads. You can therefore use copper pipe to join the units together, if practical you should not have a joint. If you use either the unfilled pipe or do your own you will need a guy to recharge the system. As to the length well it can depend on the size of pipe and refrigerant used. For example I discovered on the webs that if you use R410A refrigerant you can use thinner pipes and have runs up to 50 Metres. If in doubt ask an expert and I'm no expert its just what I have read.

However the gas is very expensive so you need to use a proper guy to refill the system. What they should do is connect up and vacuum down the system. This takes out all your gas and stores it. When the pressure is down to as near a zero as they can get (the quality of the pump they use is so important) they inject back in your own gas plus top it up with their own. I was charged 60 Euros each unit to have this done but then he is a friend of a friend.

Somebody mentioned noise. Well thats quite important to me as well. What I do notice is that they make a lot of noise when they switch on for a second or two. The beauty of the inverter type is that they never stop they just slowly settle down to a temperature maintaining speed once the room gets to the temp you set it at. This way you don't get the surges as they stop and start so therefore its quieter and of course burn less electricity.

As I said in the other thread inverter units are no different in efficiency to standard ones if they run at full speed all the time so it is very important to get the right size unit for the right size room and if in doubt go bigger on the unit i.e. if you room is 45M2 don't go for a 40M2 unit go for a 60M2 unit.

Hope that helps.

Re the wood pellets, I know they sell them in Limoux near Mr Bricolarge but they are expensive and they are sold in, wait for is, normal plastic sacks, and I thought this was suppose to be green! If you do a search on the Internet you can buy a machine for a couple of grand that you can shove a log in at one end and pellets pop out at the other. To be honest this is the sort of thing that puts you off. OK the boiler is more expensive than normal but then you need a automated hopper feeder so it does not matter if you forget to fill up the hopper. Then if you want to be really green and use your own wood or fast growing hazel to make pellets then it cost a fortune to get the machine. With the latter the screw types are the best apparently but then you are talking 6 to 8k a pop. Great your doing your thing for the environment but you will be broke after you have installed it. Do you think the greenies will then feed you because you can't afford to buy food afterwards because you spent all your money on being green, I don't think so. This level of being green is only really for the rich which I find disgusting but there you go, its now a big multi national, multi billion dollar industry getting bigger by the day.

[BIG MAC]

This has to be my daftest Idea yet...but one thing th French aren't short of is......Compost

A well tended compost heap is pretty warm...what about laying a matrix of pipes in some suitable medium within an enormous compost heap as a heat source?

I know madness!

[Devon]

From Quillan

 Great your doing your thing for the environment but you will be broke after you have installed it. Do you think the greenies will then feed you because you can't afford to buy food afterwards because you spent all your money on being green, I don't think so. This level of being green is only really for the rich which I find disgusting but there you go, its now a big multi national, multi billion dollar industry getting bigger by the day.

 

I couldn't agree more. I am a property developer in the UK. I have looked at incorporating 'green' construction methods in my last couple of projects but it seems most of these 'green' initiatives are little more than costly tokenism. I hadn't come across Heat pumps before a French plumber suggested the system. It seems to be a good idea but installation costs appear to outweigh the benifits of the systems.

Saying that, the wall mounted air systems advertised in the Brico link aren't too expensive and would work well alongside a conventional heating system.

[powerdesal]

[quote user="BIG MAC"]

This has to be my daftest Idea yet...but one thing th French aren't short of is......Compost

A well tended compost heap is pretty warm...what about laying a matrix of pipes in some suitable medium within an enormous compost heap as a heat source?

I know madness!

[/quote]

No, not madness. Unfortunately not new and original either.

Many years ago there was a guy advertising in Farmers Weekly. He offerred a service where he would dig a big hole for you, install a suitable matrix of pipes and fill with wood chips. As the chips rotted they provided heat. At the end of the rot period he would come and remove the compost and recharge with new wood chips. As I recall it was not expensive for the heat recipient but it was a pretty good money spinner for the advertiser. Wood chips sourced from thinnings after forestry commission felling ( a cheap extraction licence was needed), farmers / landowners willing to pay him to let him store the chips on their land and finally a source of compost to bag and sell. Mind you, I dont know how successful his venture was, but it sounded good.